Methods: The scanning electron microscopy (SEM) observations were made on 10 fluorosed teeth extracted from people of 30-40 years old for periodontitis reason from Tanggu area, Tianjing Province (water-drinking endemic fluorosis area), and from Xianfeng c
Methods: The scanning electron microscopy (SEM) observations were made on 10 fluorosed teeth extracted from people of 30-40 years old for periodontitis reason from Tanggu area, Tianjing Province (water-drinking endemic fluorosis area), and from Xianfeng c
方法：从燃煤污染型氟中毒病区湖北省恩施州咸丰县和饮水型氟中毒病区天津市塘沽区分别收集30-40岁因牙周炎拔除的氟斑牙，各选10颗，对照牙为我院外科门诊拔除的12颗完好正畸牙。